Green Valley Creek outside of Fairfield was dry up until Sunday's earthquake. Since then water has been flowing and residents are worried. It's not a huge rush of water, but it's enough for residents to question where it's coming from.

When water started appearing in Green Valley Creek immediately after Sunday's 6.0 earthquake, residents started emailing each other.

"They said there's water flowing in the creek right after the earthquake, what's going on? The fears are, what if there are fissures in the dam or one of the pipes is broken," Bill Mayben, Green Valley Landowners Association president, said.

There are two dams upstream from Green Valley Creek, one at Lake Frey and another at Lake Madigan.

The City of Vallejo manages the water system and on Friday, a state inspector confirmed that none of the city's dams sustained any earthquake-related damage.

Instead, the water, about 300 gallons per minute, is coming from the ground about a mile downstream from Frey Dam through fissures in the rocks caused by the earthquake.

"Our suspicion is that this phenomena, as these groundwater areas drain down as these pockets of water drain down, that it'll return to its normal flow pattern," Franz Nesterlode, Vallejo Water superintendent, said. "That's our expectation."

Residents are hoping that the water is indeed coming from the ground, and not because of any structural damage.

The Green Valley Homeowners Association is in the middle of a lawsuit with the City of Vallejo over the cost of water, so any earthquake damage would add another variable to their legal battle.

"We have 800 families here who are paying for a huge municipal water system, which Vallejo used to use, so costs are already high," Stephen Flynn, Green Valley Landowners attorney, said.

The possible silver lining in all this, if tests confirm the groundwater is safe enough, the City of Vallejo will begin treating it to be used as drinking water.